根据短文内容和首字母提示补全单词，使短文完整、正确。
People live in different kinds of houses in the world. Usually, each house has i____ own living rooms, bedrooms, kitchen and b____. Different houses have different n____. What are they? Now, let’s take a look.
A flat is usually in a building. There are usually many f____ living in the same flat building. People in a flat building s____ the same stairs（楼梯） and lift to go up and down.
A townhouse has two floors. In a townhouse, the kitchen, the living room and dining room are usually on the ground floor, and the bedrooms are usually on the f ____ floor.
A farmhouse is a house on a farm. There are many farmers living there. There is a large yard （院子） in f____ of it. There are also some “houses” for cows and hens near the farmhouse. The field is not f____ from the farmhouse, so farmers always go to the field on f____.
A dormitory is a large bedroom in a s____, and every 4—8 students share one dormitory. They share the same bathroom, but each student has his or her own bed. Students can learn how to get along well（相处）with each other in a dormitory.
左支上一点，
为双曲线的左右焦点，且
则此双曲线离心率是（ ）
